Plaquenil is used to treat or prevent malaria, a disease caused by parasites that enter the body through the bite of a mosquito. Malaria is common in areas such as Africa, South America, and Southern Asia. Plaquenil or methotrexate Chloroquine sensitive areas Plaquenil and osteoporosis Taking hydroxychloroquine long-term or at high doses may cause irreversible damage to the retina of your eye. Stop taking this medicine and call your doctor at once if you have trouble focusing, if you see light streaks or flashes in your vision, or if you notice any swelling or color changes in your eyes. It is a good idea to advise the prescribing physician whenever one uses more or less than the prescribed amount of a medication. However, in general terms, taking 400 mg of hydroxychloroquine is within a safe range for most people. The risk may also be higher with some doses of hydroxychloroquine, if you use hydroxychloroquine for longer than 5 years, or if you take certain other drugs like tamoxifen. Call your doctor right away if you have any eyesight changes like blurred or foggy eyesight, trouble focusing or reading, or trouble seeing in dim light. Plaquenil is also an antirheumatic medicine and is used to treat symptoms of rheumatoid arthritis and discoid or systemic lupus erythematosus. This medicine is not effective against all strains of malaria. What happens if you take too much hydroxychloroquine Plaquenil Overdose - Antibiotics Home Page, I accidentally took two 200mg tabs of hydroxychloroquine. Hydroxychloroquine methotrexate sulfasalazine azathioprine lefludomide Hydroxychloroquine oral tablet is available as a brand-name drug and a generic drug. Brand name Plaquenil. Hydroxychloroquine comes only as a tablet you take by mouth. Hydroxychloroquine is used to treat malaria, lupus erythematosus, and rheumatoid arthritis. Hydroxychloroquine Side Effects, Dosage, Uses, and More. Hydroxychloroquine Indications, Side Effects, Warnings -. What next if plaquenil doesn't work?. I can't believe you were told to stop taking plaquenil after only 6 months since it can take up to one YEAR to achieve full benefits! I don't know much about any sort of withdrawal but if I were you I'd start taking it again. I'd also have your thyroid checked. I'm hypothyroid and take levo along with he plaquenil. Here are side effect From taking too many antacids. The least important side effects are constipation or diarrhea. Large amounts of calcium carbonate -containing antacids can affect the balances of calcium and acid in the body and damage the kidneys. Take this medication with a meal or a glass of milk to prevent stomach upset. Common side effects include nausea, loss of appetite, headache, and diarrhea. Plaquenil can cause blurred vision and dizziness. Do not drive or operate heavy machinery until you know how it affects you.